The Second Republic maintained moderate economic development. The cultural hubs of interwar Poland – Warsaw, Kraków, Poznań, Wilno and Lwów – became major European cities and the sites of internationally acclaimed universities and other institutions of higher education.

The Second Polish Republic was a parliamentary democracy from 1919 (see Small Constitution of 1919) to 1926, with the President having limited powers. The Parliament elected him, and he could appoint the Prime Minister as well as the government with the Sejm's (lower house's) approval, but he could only dissolve the Sejm with the Senate's consent. Moreover, his power to pass decrees was limited by the requirement that the Prime Minister and the appropriate other Minister had to verify his decrees with their signatures. Poland was one of the first countries in the world to recognize women's suffrage. Women in Poland were granted the right to vote on 28 November 1918 by a decree of Józef Piłsudski.[12]

The interwar Poland had a considerably large army of 950,000 soldiers on active duty: in 37 infantry divisions, 11 cavalry brigades, and two armored brigades, plus artillery units. Another 700,000 men served in the reserves. At the outbreak of the war, the Polish army was able to put in the field almost one million soldiers, 4,300 guns, 1,280 tanks and 745 aircraft.[14]

The training of the Polish army was thorough. The N.C.O.s were a competent body of men with expert knowledge and high ideals. The officers, both senior and junior, constantly refreshed their training in the field and in the lecture-hall, where modern technical achievement and the lessons of contemporary wars were demonstrated and discussed. The equipment of the Polish army was less developed technically than that of Nazi Germany and its rearmament was slowed down by confidence in Western European military support and by budget difficulties.[15]

After regaining its independence, Poland was faced with major economic difficulties. In addition to the devastation wrought by World War I, the exploitation of the Polish economy by the German and Russian occupying powers, and the sabotage performed by retreating armies, the new republic was faced with the task of economically unifying disparate economic regions, which had previously been part of different countries.[16] Within the borders of the Republic were the remnants of three different economic systems, with five different currencies (the German mark, the Russian ruble, the Austrian crown, the Polish marka and the Ostrubel)[16] and with little or no direct infrastructural links. The situation was so bad that neighboring industrial centers as well as major cities lacked direct railroad links, because they had been parts of different nations. For example, there was no direct railroad connection between Warsaw and Kraków until 1934. This situation was described by Melchior Wańkowicz in his book Sztafeta.

On top of this was the massive destruction left after both World War I and the Polish–Soviet War. There was also a great economic disparity between the eastern (commonly called Poland B) and western (called Poland A) parts of the country, with the western half, especially areas that had belonged to the German Empire being much more developed and prosperous. Frequent border closures and a customs war with Germany also had negative economic impacts on Poland. In 1924 Prime Minister and Economic Minister Władysław Grabski introduced the złoty as a single common currency for Poland (it replaced the Polish marka), which remained a stable currency. The currency helped Poland to control the massive hyperinflation. It was the only country in Europe able to do this without foreign loans or aid.[17] The average annual growth rate (GDP per capita) was 5.24% in 1920–29 and 0.34% in 1929–38.[18]

Hostile relations with neighbours were a major problem for the economy of interbellum Poland. In the year 1937, foreign trade with all neighbours amounted to only 21% of Poland's total. Trade with Germany, Poland's most important neighbour, accounted for 14.3% of Polish exchange. Foreign trade with the Soviet Union (0.8%) was virtually nonexistent. Czechoslovakia accounted for 3.9%, Latvia for 0.3%, and Romania for 0.8%. By mid-1938, after the Anschluss of Austria, Greater Germany was responsible for as much as 23% of Polish foreign trade.

The basis of Poland's gradual recovery after the Great Depression was its mass economic development plans (see Four Year Plan), which oversaw the building of three key infrastructural elements. The first was the establishment of the Gdynia seaport, which allowed Poland to completely bypass Gdańsk (which was under heavy German pressure to boycott Polish coal exports). The second was construction of the 500-kilometer rail connection between Upper Silesia and Gdynia, called Polish Coal Trunk-Line, which served freight trains with coal. The third was the creation of a central industrial district, named COP – Central Industrial Region (Centralny Okręg Przemysłowy). Unfortunately, these developments were interrupted and largely destroyed by the German and Soviet invasion and the start of World War II.[20] Other achievements of interbellum Poland included Stalowa Wola (a brand new city, built in a forest around a steel mill), Mościce (now a district of Tarnów, with a large nitrate factory), and the creation of a central bank. There were several trade fairs, with the most popular being Poznań International Fair, Lwów's Targi Wschodnie, and Wilno's Targi Północne. Polish Radio had ten stations (see Radio stations in interwar Poland), with the eleventh one planned to be opened in the autumn of 1939. Furthermore, in 1935 Polish engineers began working on the TV services. By early 1939, experts of the Polish Radio built four TV sets. The first movie broadcast by experimental Polish TV was Barbara Radziwiłłówna, and by 1940, regular TV service was scheduled to begin operation.[21]

Industry and communications in Poland before the start of World War II

According to the 1939 Statistical Yearbook of Poland, total length of railways of Poland (as for 31 December 1937) was 20,118 kilometres (12,501 miles). Rail density was 5.2 kilometres (3.2 miles) per 100 square kilometres (39 square miles). Railways were very dense in western part of the country, while in the east, especially Polesie, rail was non-existent in some counties. During the interbellum period, the Polish government constructed several new lines, mainly in the central part of the country (see also Polish State Railroads Summer 1939). Construction of extensive Warszawa Główna railway station was never finished due to the war, and Polish railroads were famous for their punctuality (see Luxtorpeda, Strzała Bałtyku, Latający Wilnianin).

In the interbellum, road network of Poland was dense, but the quality of the roads was very poor – only 7% of all roads was paved and ready for automobile use, and none of the major cities were connected with each other by a good-quality highway. Poles built in 1939 only one highway, 28 km of straight concrete road connecting villages Warlubie and Osiek (mid-northern Poland). It was designed by Italian engineer Piero Puricelli.

CWS T-1Torpedo was the first serially-built car manufactured in Poland.

In the mid-1930s, Poland had 340,000 kilometres (211,266 miles) of roads, but only 58,000 had hard surface (gravel, cobblestone or sett), and 2,500 were modern, with asphalt or concrete surface. In different parts of the country, there were sections of paved roads, which suddenly ended, and were followed by dirt roads.[23] The poor condition of the roads was the result of both long-lasting foreign dominance and inadequate funding. On 29 January 1931, the Polish Parliament created the State Road Fund, the purpose of which was to collect money for the construction and conservation of roads. The government drafted a 10-year plan, with road priorities: a highway from Wilno, through Warsaw and Kraków, to Zakopane (called Marshal Piłsudski Highway), asphalt highways from Warsaw to Poznań and Łódź, as well as a Warsaw ring road. However, the plan turned out to be too ambitious, with insufficient money in the national budget to pay for it. In January 1938, the Polish Road Congress estimated that Poland would need to spend three times as much money on roads to keep up with Western Europe.

Ciągówka Ursus was the first Polish farm tractor, produced in the years 1922-1927 in the Ursus Factory.

Statistically, the majority of citizens lived in the countryside (75% in 1921). Farmers made up 65% of the population. In 1929, agricultural production made up 65% of Poland's GNP.[25] After 123 years of partitions, regions of the country were very unevenly developed. Lands of former German Empire were most advanced; in Greater Poland and Pomerelia, crops were on Western European level.[26] The situation was much worse in parts of Congress Poland, Eastern Borderlands, and former Galicia, where agriculture was most backward and primitive, with a large number of small farms, unable to succeed in either the domestic and international market. Another problem was the overpopulation of the countryside, which resulted in chronic unemployment. Living conditions were so bad that in several eastern regions, such as counties inhabited by the Hutsuls, there was permanent starvation.[27] Farmers rebelled against the government (see: 1937 peasant strike in Poland), and the situation began to change in the late 1930s, due to construction of several factories for the Central Industrial Region, which gave employment to thousands of countryside residents.

Beginning in June 1925 there was a customs' war with the revanchist Weimar Republic imposing trade embargo against Poland for nearly a decade; involving tariffs, and broad economic restrictions. After 1933 the trade war ended. The new agreements regulated and promoted trade. Germany became Poland's largest trading partner, followed by Britain. In October 1938 Germany granted a credit of Rm 60,000,000 to Poland (120,000,000 zloty, or £4,800,000) which was never realized, due to the outbreak of war. Germany would deliver factory equipment and machinery in return for Polish timber and agricultural produce. This new trade was to be in addition to the existing German-Polish trade agreements.[28][29]

From the 1920s the Polish government excluded Jews from receiving government bank loans, public sector employment, and obtaining business licenses. From the 1930s measures were taken against Jewish shops, Jewish export firms, Shechita as well as limitations were placed on Jewish admission to the medical and legal professions, Jews in business associations and the enrollment of Jews into universities. The far-right National Democracy (Endecja from the abbreviation "ND") often organized anti-Jewish boycotts.[30] Following the death of Józef Piłsudski in 1935, the Endecja intensified their efforts which triggered violence in extreme cases in smaller towns across the country.[30] In 1937, the National Democracy movement passed resolutions that "its main aim and duty must be to remove the Jews from all spheres of social, economic, and cultural life in Poland".[30] The government in response organized the Camp of National Unity (OZON), which in 1938 took control of the Polish Sejm and subsequently drafted anti-Semitic legislation similar to the Anti-Jewish laws in Germany, Hungary, and Romania. OZON advocated mass emigration of Jews from Poland, numerus clausus (see also Ghetto benches), and other limitation on Jewish rights. According to William W. Hagen by 1939, prior to the war, Polish Jews were threatened with conditions similar to those in Nazi Germany.[31]

The pre-war government also restricted rights of people who declared Ukrainian nationality, belonged to the Eastern Orthodox Church and inhabited the Eastern Borderlands of the Second Polish Republic.[32][33][34] The Ukrainian language was restricted in every field possible, especially in governmental institutions, and the term "Ruthenian" was enforced in an attempt to ban the use of the term "Ukrainian".[35] Ukrainians were categorized as uneducated second-class peasants or third world people and rarely settled outside the Eastern Borderland region due to the prevailing Ukrainophobia and restrictions imposed. Numerous attempts at restoring the Ukrainian state were suppressed and any existent violence or terrorism initiated by the Organization of Ukrainian Nationalists was emphasized to create an image of a "brutal Eastern savage".[36]

In 1919, the Polish government introduced compulsory education for all children aged 7 to 14, in an effort to limit illiteracy, which was widespread especially in the former Russian Partition and the Austrian Partition of eastern Poland. In 1921, one-third of citizens of Poland remained illiterate (38% in the countryside). The process was slow, but by 1931, the illiteracy level had dropped to 23% overall (27% in the countryside) and further down to 18% in 1937. By 1939, over 90% of children attended school.[22][37] In 1932, Minister of Religion and Education Janusz Jędrzejewicz carried out a major reform which introduced two main levels of education: common school (szkoła powszechna), with three levels – 4 grades + 2 grades + 1 grade; and middle school (szkoła średnia), with two levels – 4 grades of comprehensive middle school and 2 grades of specified high school (classical, humanistic, natural and mathematical). A graduate of middle school received a small matura, while a graduate of high school received a big matura, which enabled them to seek university-level education.

Theatre was immensely popular in the interbellum, with three main centers in the cities of Warsaw, Wilno and Lwów. Altogether, there were 103 theaters in Poland and a number of other theatrical institutions (including 100 folk theaters). In 1936, different shows were seen by 5 million people, and main figures of Polish theatre of the time were Juliusz Osterwa, Stefan Jaracz, and Leon Schiller. Also, before the outbreak of the war, there were approximately one million radios (see Radio stations in interwar Poland).

The administrative division of the Republic was based on a three-tier system. On the lowest rung were the gminy, local town and village governments akin to districts or parishes. These were then grouped together into powiaty (akin to counties), which, in turn, were grouped as województwa (voivodeships, akin to provinces).

Historically, Poland was a nation of many nationalities. This was especially true after independence was regained in the wake of World War I and the subsequent Polish–Soviet War ending at Peace of Riga. The census of 1921 shows 30.8% of the population consisted of ethnic minorities,[41] compared with a share of 1.6% (solely identifying with a non-Polish ethnic group) or 3.8% (including those identifying with both the Polish ethnicity and with another ethnic group) in 2011.[42] The first spontaneous flight of about 500,000 Poles from the Soviet Union occurred during the reconstitution of sovereign Poland. In the second wave, between November 1919 and June 1924 some 1,200,000 people left the territory of the USSR for Poland. It is estimated that some 460,000 of them spoke Polish as the first language.[43] According to the 1931 Polish Census: 68.9% of the population was Polish, 13.9% were Ukrainian, around 10% Jewish, 3.1% Belarusian, 2.3% German and 2.8% other, including Lithuanian, Czech, Armenian, Russian, and Romani. The situation of minorities was a complex subject and changed during the period.[5]

By 1931, Poland had the second largest Jewish population in the world, with one-fifth of all the world's Jews residing within its borders (approx. 3,136,000).[41] The urban population of interbellum Poland was rising steadily; in 1921, only 24% of Poles lived in the cities, in the late 1930s, that proportion grew to 30%. In more than a decade, the population of Warsaw grew by 200,000, Łódź by 150,000, and Poznań – by 100,000. This was due not only to internal migration, but also to an extremely high birth rate.[22]

The Second Mountain Brigade of the Polish Legions in World War I officers establishing the Polish-Czechoslovak border near the summit of Popadia in Gorgany during the formation of the Second Republic, 1915

The Second Polish Republic was mainly flat with average elevation of 233 metres (764 ft) above sea level, except for the southernmost Carpathian Mountains (after World War II and its border changes, the average elevation of Poland decreased to 173 metres (568 ft)). Only 13% of territory, along the southern border, was higher than 300 metres (980 ft). The highest elevation in the country was Mount Rysy, which rises 2,499 metres (8,199 ft) in the Tatra Range of the Carpathians, approximately 95 kilometres (59 miles) south of Kraków. Between October 1938 and September 1939, the highest elevation was Lodowy Szczyt (known in the Slovak language as Ľadový štít), which rises 2,627 metres (8,619 ft) above sea level. The largest lake was Lake Narach.

Physical map of the Second Polish Republic

The country's total area, after the annexation of Zaolzie, was 389,720 square kilometres (150,470 sq mi). It extended 903 kilometres (561 miles) from north to south and 894 kilometres (556 miles) from east to west. On 1 January 1938, total length of boundaries was 5,529 kilometres (3,436 miles), including: 140 kilometres (87 miles) of coastline (out of which 71 kilometres (44 miles) were made by the Hel Peninsula), the 1,412 kilometres (877 miles) with Soviet Union, 948 kilometers with Czechoslovakia (until 1938), 1,912 kilometres (1,188 miles) with Germany (together with East Prussia), and 1,081 kilometres (672 miles) with other countries (Lithuania, Romania, Latvia, Danzig). The warmest yearly average temperature was in Kraków among major cities of the Second Polish Republic, at 9.1 °C (48.4 °F) in 1938; and the coldest in Wilno (7.6 °C or 45.7 °F in 1938). Extreme geographical points of Poland included Przeświata River in Somino to the north (located in the Braslaw county of the Wilno Voivodeship); Manczin River to the south (located in the Kosów county of the Stanisławów Voivodeship); Spasibiorki near railway to Połock to the east (located in the Dzisna county of the Wilno Voivodeship); and Mukocinek near Warta River and Meszyn Lake to the west (located in the Międzychód county of the Poznań Voivodeship).

Almost 75% of the territory of interbellum Poland was drained northward into the Baltic Sea by the Vistula (total area of drainage basin of the Vistula within boundaries of the Second Polish Republic was 180,300 square kilometres (69,600 square miles), the Niemen (51,600 square kilometres or 19,900 square miles), the Odra (46,700 square kilometres or 18,000 square miles) and the Daugava (10,400 square kilometres or 4,000 square miles). The remaining part of the country was drained southward, into the Black Sea, by the rivers that drain into the Dnieper (Pripyat, Horyn and Styr, all together 61,500 square kilometres or 23,700 square miles) as well as Dniester (41,400 square kilometres or 16,000 square miles)

Polish war plans (Plan West and Plan East) failed as soon as Germany invaded in 1939. The Polish losses in combat against Germans (killed and missing in action) amounted to ca. 70,000 men. Some 420,000 of them were taken prisoners. Losses against the Red Army (which invaded Poland on 17 September) added up to 6,000 to 7,000 of casualties and MIA, 250,000 were taken prisoners. Although the Polish army – considering the inactivity of the Allies – was in an unfavorable position – it managed to inflict serious losses to the enemies: 14,000 German soldiers were killed or MIA, 674 tanks and 319 armored vehicles destroyed or badly damaged, 230 aircraft shot down; the Red Army lost (killed and MIA) about 2,500 soldiers, 150 combat vehicles and 20 aircraft. The Soviet invasion of Poland, and lack of promised aid from the Western Allies, contributed to the Polish forces defeat by 6 October 1939.

A popular myth is that Polish cavalry armed with lances charged German tanks during the September 1939 campaign. This often repeated account, first reported by Italian journalists as German propaganda, concerned an action by the Polish 18th Lancer Regiment near Chojnice. This arose from misreporting of a single clash on 1 September 1939 near Krojanty, when two squadrons of the Polish 18th Lancers armed with sabers surprised and wiped out a German infantry formation with a mounted sabre charge. Shortly after midnight the 2nd (Motorized) Division was compelled to withdraw by Polish cavalry, before the Poles were caught in the open by German armored cars. The story arose because some German armored cars appeared and gunned down 20 troopers as the cavalry escaped. Even this failed to persuade everyone to reexamine their beliefs—there were some who thought Polish cavalry had been improperly employed in 1939.

Blanke, R. Orphans of Versailles. The Germans in Western Poland, 1918–1939 (1993)

Gutman, Y. et al. eds. The Jews of Poland Between Two World Wars (1989).

Landau, Z. and Tomaszewski, J. The Polish Economy in the Twentieth Century (Routledge, 1985)

Moklak, Jaroslaw. The Lemko Region in the Second Polish Republic: Political and Interdenominational Issues 1918–1939 (2013); covers Old Rusyns, Moscophiles and National Movement Activists, & the political role of the Greek Catholic and Orthodox Churches